Mine mooring cutter



19, 1946. E c cR G MINE MOORING CUTTER Filed April 30, 1941 ATI'ORNEY Patented Mar. 19, 1946 MINE lvioonmoI CUTTER.

Edward 0. Craig, United States Navy Application April 30, 1941, Serial No. 391,174

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 1 Claim.

- This invention relates to a mine mooring cutter,- and' has for an object to provide an improved device for mechanically cutting moorings, cables or anchor chains of submarine mines.

A further object of this invention is to provide a mine mooring cutter which utilizes the tension in the sweep cable to complete a cutting operation initiated by the mine mooring contacting with the serrated V-shaped knife.

Still a further object of this invention is to provide a mine mooring cutter having a serrated knife for initiating the cutting action of the mooring and having a pivoted knife connected to the cable and released for pivotal action by a trigger contacted by the mine mooring to pivot this knife and complete the cutting operation.

Still a further object of this invention is to providea combination of a shear knife and a pivotal knife in a mine mooring cutter which cooperate to cut a mine mooring, and then after the cutting is completed serve to by-pass a subsequent mine mooring to a further cutting device located in the sweep cable.

With the foregoing and other objects in view,

the invention consists in the construction, combination and arrangement of parts hereinafter described and illustrated in the drawing, in which:

Fig. 1 is an elevatlonal view of the mine mooring cutter of this invention;

Fig. 2 is an edge view of the cutter of Fig. 1;

Fig. 3 is a plan view of the pivoted knife releasing trigger; and

Fig. 4 is a plan view of the pivoted knife.

There is shown at Ill the mine mooring cutter of this invention, comprising a body 9, secured within the mine sweep cable I 2 by rotatable joints l3 and I4, thereby enabling an extending fin H to easily rotate the body 9 to a horizontal position as the cutter H3 is pulled through the water by the sweep cable l2 in the direction of the arrow 15. The rearward joint I3 is secured to the body 9 by a pivoted link l6, while'the forward joint M has a link I! pivotally securing it as at Hi to an arm 20, which, in turn, is pivoted at 2| to the body 9. The body 9 is provided at 22 with a serrated V-knife, one of whose edges 23 lines up with the forward edge 24 of the body 9.

This forward edge 24 in turn is substantially in alignment with the forward portion of sweep cable l2 so that as the cutter is drawn through the water between a pair of mine sweepers a mine mooring or anchor cable 25, struck by the sweep cable l2, will travel along the forward sweep cable I2 over the forward leading edge 24 of body 9, along the jaw 23 and into the serrated v knife 22 to be at least partially severed thereby. Extending across the open jaw 23 is a trigger 26 pivoted at 21 to one side of body 3. A hooked finger 28 on trigger 26 is provided with a boss 36, extending at right angles to the plane of the trigger 26 through a suitable opening 3! in the body 9 to the opposite side thereof.

On this opposite side, that is, the upper side, as in Fig. 1, there is mounted a knife 32, pivoted to the body 9, as at 33. This pivoted knife 32 is provided with a notch 34 into which the boss 39 of trigger 26 extends, preventing this knife from pivoting in a counter-clockwise direction, as shown by arrow 35. This knife 32 is generally circular except for a sector cut away, and in this sector edge there is provided a U-shaped knife edge 36 whose medial radial distance from the knife pivot 33 is substantially equal to the distance between the pivot 33 and the center of the serrated V-knife 22. Secured to the pivoted knife 32 adjacent the end of the notch 32 is a flexible metallic strap 3'! which is anchbred thereto as by a rivet 38, while its opposite end is secured by a bracket 46 to the end of arm 26 adjacent pivot l8.

In operation, as the mine mooring 25 enters the serrated V-knife 22 it simultaneously strikes the hooked end 4! of the trigger 26, causing the trigger 26 to shear through the shear pin 42 ex tending through suitably aligned holes in the trigger 26 and body 9. As the shear pin 52 is cut through the trigger 26 yields under pressure of the mine mooring to withdraw the boss 30 in the notch 34, causing it to release the knife 32. With the pivoted knife thus released, the tension in the forward sweep l2 pulls arm 20 to the position 20' about its pivot 2|, and simultaneously pulls the flexible strap 3? to the position 37', thus pivoting the knife 32 about bringing the cutter edge 36 to the position 36' at the inner end of the serrated V-knife 22.

As it travels through this position it does so in a very quick motion and under the tension of the towing sweep cable 2. The knife edge 36 will thus shear through the mine mooring 25 which has been at least partly sheared by the serrated edges of the V-knife 22. The cutting of the mine mooring 25 is thus assured. Then, the circular edge 43 of the rotatable knife 32 guards a ainst a subsequent'mine mooring entering the V-km'fe 22 and insures instead that it will travel there-- over past the following sweep cable I2 to a subsequent similar cutting device, where it will be positively severed in alike manner.

Other modifications and changes in the'numher and arrangement of the parts may be made by those skilled in the art without departing from t the nature of this invention, within the scope of what is hereinafter claimed.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the ,payment of any royalties thereon'or therefor. i

Having thus set forth and disclosed the nature of this invention, what is claimed is:

A mine mooring cutter comprising a fin body,

a pair of sweep cable members secured to 'bpp'osite sides of said fin body, one of said cable sweep,

mounted blade being adapted to sweep over said blade secured on said fin body, a tension member secured at one end to the cable securing end of said link, the other end of said tension member being secured to the periphery of said rotatable knife body in a position tending to rotate said knife blade body, a bell crank trigger member pivotedcentrally of its ends onsaidtfin body, one ehd'roffsaidtrig'ger member extending across said fixed blade, a boss on the other end or said bell crank trigger member extending into a recess in 'said rotatable knife blade body, whereby when amine Lmooring traveling along said link connected sweep cable towing member abuts said fixed knife blade, it pivots said trigger member *to withdraw said trigger boss from said recess in said knife blade body, freeing it for rotation by said tension member secured to said link contii'e'cted "sweep 'c'aibl'e towing member and causing said rotatable knife member to cut the mooring cable against said fixed knife :blade, said towing 'cable member serving to rotate said :rotatable :knife member over said fixed blade.

EDWARD 1C. CRI'AIG. 

